The treatment and relief of pain is one of the most common reasons patients seek medical evaluation. Pain has been defined by the International Association for the Study of Pain as the response to real or perceived tissue trauma. The word “pain” derives from the Latin “poena,” or punish. Postoperative pain is an example of acute pain. During the intraoperative period, anesthesiologists focus attention on helping abolish pain and discomfort associated with noxious stimuli and associated surgical tissue trauma. It is now recognized that many current modalities used to treat acute postoperative pain are incomplete and/or cause morbidity.
Surgical pain causes a generalized and biphasic response. The first response due to direct surgical trauma produces transduction of nociceptive input via c-fiber and a-delta activation leading to transmission, modulation and perception of pain signals in the peripheral and central nervous system. At the time of surgical trauma, complex inflammatory processes are triggered, leading to further afferent noxious input, leading to peripheral and secondary central nociceptive sensitization. This results in a reduction in the threshold of surrounding nociceptors with increased excitation and recruitment of nociceptive afferents.
Surgical trauma results in a complex local release of inflammatory mediators further contributing to peripheral sensitization and recruitment of higher threshold nociceptors, giving rise to secondary hyperalgesia; where non-painful stimuli like light touch is perceived as painful.
Central sensitization refers to processes occurring at the spinal dorsal root ganglion and higher regions of the central nervous system in response to ongoing afferent nociceptor barrage. This leads to an expansion of the nociceptive field size, increased and magnified response to nociceptive stimuli, and a reduction in the afferent stimuli threshold that is perceived as painful.
The present invention discloses an opioid sparing anesthetic formulation comprising Bupivacaine hydrochloride, Ketamine, and Ketorolac which is effective to significantly reduce postoperative nausea and vomiting and enhance postoperative pain relief as compared to existing prior art anesthetics. Without wishing to limit the present invention to any theory or mechanism, it is believed that the formulations of the present invention are advantageous because they feature drugs that, in synergism, provide long-lasting effects and are opioid-sparing.
Any feature, or combination of features, described herein are included within the scope of the present invention provided that the features included in any such combination are not mutually inconsistent as will be apparent from the context, this specification, and the knowledge of one of ordinary skill in the art. Additional advantages and aspects of the present invention are apparent in the following detailed description and claims.